title: Conformational transitions during FtsK translocase activation of individual XerCD-dif recombination complexes.
abstract: Three single-molecule techniques have been used simultaneously and in tandem to track the formation in vitro of single XerCD-dif recombination complexes. We observed the arrival of the FtsK translocase at individual preformed synaptic complexes and demonstrated the conformational change that occurs during their activation. We then followed the reaction intermediate transitions as Holliday junctions formed through catalysis by XerD, isomerized, and were converted by XerC to reaction products, which then dissociated. These observations, along with the calculated intermediate lifetimes, inform the reaction mechanism, which plays a key role in chromosome unlinking in most bacteria with circular chromosomes.
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
authors.forename: Pawel
authors.initials: P
authors.lastname: Zawadzki
authors.forename: Peter F J
authors.initials: PF
authors.lastname: May
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Baker
authors.forename: Justin N M
authors.initials: JN
authors.lastname: Pinkney
authors.forename: Achillefs N
authors.initials: AN
authors.lastname: Kapanidis
authors.forename: David J
authors.initials: DJ
authors.lastname: Sherratt
authors.forename: Lidia K
authors.initials: LK
authors.lastname: Arciszewska
mesh_terms: D000465:Algorithms; D001483:Base Sequence; D055162:Biocatalysis; D023902:Chromosome Pairing; D002876:Chromosomes, Bacterial / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D045566:DNA, Cruciform / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D019426:Integrases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence / Q000379:methods; D008957:Models, Genetic; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D011995:Recombination, Genetic; D013379:Substrate Specificity
chemical_list: D004269:DNA, Bacterial; D045566:DNA, Cruciform; D029968:Escherichia coli Proteins; C096452:FtsK protein, E coli; D008565:Membrane Proteins; C473360:XerC protein, E coli; D019426:Integrases; C473361:XerD protein, E coli
keywords: chromosome segregation; protein–DNA interaction; single-molecule FRET; site-specific DNA recombination; tethered fluorophore motion